Neural Mechanisms of Visual Crowding

视觉拥挤的神经机制

• 批准号: 10365136
• 负责人: Anirvan S. Nandy
• 金额: $ 41.76万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10365136
• 关键词: Address; Affect; Animals; Area; Attention; Blindness; Cells; Chronic; Crowding; Future; Impairment; Individual; Intervention Studies; Investigation; Knowledge; Location; Macular degeneration; Mediating; Nature; Neurons; Output; Pathway interactions; Patients; Perception; Performance; Peripheral; Population; Process; Protocols documentation; Radial; Research; Resources; Retina; Saccades; Scotoma; Sensory; Shapes; Signal Transduction; Site; Stimulus; Target Populations; Testing; Time; Vision; Visual; Visual Perception; Visual system structure; area V4; awake; base; density; excitatory neuron; extrastriate visual cortex; fovea centralis; gaze; inhibitory neuron; interest; neural correlate; neuromechanism; nonhuman primate; novel; object recognition; oculomotor; receptive field; relating to nervous system; spatiotemporal

Project Summary Visual perception is an active process of information selection. Two critical components of this selection process are the mechanisms of spatial attention and saccadic eye-movements. Attention allows us to deploy limited neural resources for privileged processing of salient stimuli; saccades allow us to bring stimuli of interest to the center of gaze for detailed inspection. The dynamic interplay of attention and saccades is particularly prominent in peripheral vision where inappropriate integration of contextual information has been proposed as one of the underlying mechanisms of visual crowding. Visual crowding is the inability to identify stimuli amidst clutter and is a fundamental bottleneck to object recognition in peripheral vision. It is particularly detrimental in the case of patients with central vision loss such as macular degeneration (MD), since these individuals rely on a peripheral retinal locus (PRL) for object recognition tasks. Crowding zones, the area in visual space over which distractors affect target identification, are markedly elongated along the radial axis aligned with the fovea in normal vision. Crowding zones undergo systematic reorganization in MD patients with an elongated component along the radial PRL axis. Despite decades of research, the neural underpinnings of crowding and that of the elongated shape of crowding zones remain unknown. In this proposal we will bridge these knowledge gaps in the context of the activity of six neural sub-populations – two cell classes (inhibitory and excitatory neurons) in three layers (superficial, input, deep) – that are fundamental components of the sensory laminar cortical circuit. Our broad hypothesis is that sub-population specific activity dynamics form the substrate for contextual interactions underlying crowding and for the formation and re-organization of crowding zones. We propose to answer several key questions regarding this hypothesis. What are the laminar mechanisms of contextual modulation in crowding zones (Aim 1)? What the spatio-temporal dynamics of peri- saccadic activity in the laminar cortical circuit (Aim 2)? What are the neural mechanisms of crowding zone reorganization following central vision zone (Aim 3)? We will achieve these aims using high-density laminar neural recordings in visual area V4 of awake non-human primates. V4, a critical node in the object recognition pathway, that also receives strong attention related and oculomotor signals, is ideally suited for these investigations. The results of these investigations will uncover the neural mechanisms of crowding, provide a broad framework for visual form processing in the periphery and inform possible future intervention studies in central vision loss.

项目概要 视觉感知是信息选择的主动过程，其中有两个关键组成部分。 过程是空间注意力和扫视眼球运动的机制，使我们能够部署注意力。 用于处理显着刺激的有限神经资源使我们能够带来刺激； 对注视中心进行详细检查的兴趣是注意力和扫视的动态相互作用。 在周边视觉中尤其突出，其中上下文信息的不适当整合 视觉拥挤的潜在机制之一被认为是无法识别。 杂乱中的刺激是周边视觉中物体识别的基本瓶颈。 黄斑变性 (MD) 等中心视力丧失患者的痛苦，因为这些 个人依靠视网膜周边区域（PRL）来执行物体识别任务，即拥挤区域。 干扰物影响目标识别的视觉空间沿径向轴明显拉长 MD 患者的拥挤区与正常视力的中央凹对齐。 尽管经过数十年的研究，其神经基础仍然沿径向 PRL 轴延伸。 拥挤和拥挤区域的拉长形状仍然未知，在本提案中，我们将弥合。 这些知识差距是在六个神经亚群——两个细胞类别（抑制性细胞）的活动背景下的 和兴奋性神经元）分为三层（浅层、输入层、深层）——它们是神经元的基本组成部分 我们的广泛假设是，亚群的特定活动动态形成了感觉层状皮质回路。 拥挤的情境互动以及拥挤的形成和重组的基础 我们建议回答有关该假设的几个关键问题：什么是层流。 拥挤区域的情境调节机制（目标 1）是什么？ 层状皮质回路中的扫视活动（目标 2）是什么？拥挤区的神经机制是什么？ 中央视觉区域后的重组（目标 3）？我们将使用高密度层流来实现这些目标 清醒的非人类灵长类动物 V4 视觉区域的神经记录，这是物体识别的关键节点。 通路也接收强烈的注意力相关信号和动眼神经信号，非常适合这些 这些研究的结果将揭示拥挤的神经机制，提供一个新的思路。 外围视觉形式处理的广泛框架，并为未来可能的干预研究提供信息 中心视力丧失。